What is a Relational Database?

What is Relational Database
What is Relational Database

What is a Relational Database Management Studio, Model, in access, schema, sql, usef for, definition etc..

Hey what’s up everyone. Welcome back to your second database design series. This video we’re going to be talking about the relation very basic. Don’t freak out with this math. We’re not going to go super in-depth with Matthew and know more about the math.

I have blogs on the website about that killed Kurt come forward slash blogs advertising not box advertising house advertising anyway. Basically your relation is just a connection between data. So let’s just think of silly example if we have the two sets of numbers 2 4 and the other set was 6 8 and then we kind of combine these sets. So we kind of life crossed here and then we crossed that again.

And one of these cross is our new sets we have the combined set of six. And know we have a combined set of six for me that combines a tune that combines a and like you’re probably wondering like what the heck does THAT have to do with database design. Well some what we kind of do the same thing with database design relation in relational database comes from this mathematic concept but rather than combining sets of numbers we’re combining attributes of real world things.

So let’s apply this to the database first you need to know two terms. The first one is an entity. The second one is for you. So an entity is anything we store data about attributes are the things that we store. So if an entity is a person an attribute would be their name their username and password their hair color their address their phone number their relationships that the person they’re in a relationship with the orders that they’ve made or whatever whatever it is.

It just depends on what you need to store for that specific application. So Anthony is what we store the data about the tribute is what we store when we apply this to this. This connection with the the relation we have the Freeview types and the attribute values. So let’s say we have this person over here and we’ll name them Caillaud because it’s an awesome name.

All right. And then we will also give them a user name. Caleb Currie with no spaces. And we give them the password PI 2:59 and then over here we have the set of attributes for a table we have name user name and password. We can make this connection of data. So the name is Caleb the user name will curry passwords PI 1 2 3.

That makes sense although graphically it looks like a mess. So we store these in teams which is exactly what we were doing with the relation’s So we have all of your inner columns we have we have a name and then we have the user name and then the password. Don’t worry if you can’t read my handwriting you get it. We started this in a table.

All right. So these are the things we need to connect with this person over here which we named Caleb and I actually raced them whatever. What does that that. So that’s cool. And we want to store this information in this table which is a graphical way to say to illustrate how we’re storing data in a database. So we take his name.

We take his username cable courier we take his password I to three we kind of get this same concept. It almost looks like a spreadsheet that we talk on the last day although it is slightly different and we’ll be talking about as time goes on. This guy is the entity that we’re storing information about. These are the attributes that we need to store about this person or any other person. So we enter specific values for each one of these attributes to make the relation between the attributes and the entity that makes somewhat sense. And if it doesn’t don’t freak out it’s ok.

I mean this is complex thought and you don’t necessarily need to understand every single detail to design a database. So I’m just trying to explain things and we’ll get through it. These are the attributes of this person. This entity an entity is basically just anything we store data about.  It’s something can be a person in this case but it can also be in order.

What is a Relational Database Management Studio?

It can be a customer can be a client it can be a employee an employer whatever it is. It doesn’t have to be a person. So now the relation idea and you kind of understand that we’re just making the connection between the attributes and the entity the value the entity attributes. We’re entering the database. That’s that’s kind of a weak explanation but honestly it doesn’t really matter that much for getting into a basic database design.

So if you can learn more about that look up relational database design you’ll figure it out. So now we have the entity over there. And then we have 36 so in table terms you probably know rows and columns you might not know specifically what they are. I’m going to tell you this right here in a row.  You see that you run that space here. I think we’re good. Yeah.

So this all of these values are erro. So I row is all of the attribute values for a specific entity. So this row and these are just going this this row points to that entity that person pretty simple a column or all of the values for a specific attribute type. So the attributes that we could have another person Billie-Jo up and his name is password can be within you and his name can be. And this is another person in our table. So this is talking about a different person.

We have his first number you seem pretty chill. All this row is talking about this and the user name is a call where we have all of the attribute types. Username. So Caleb. Billy Joe and whatever more we put more values into the table. So once again a little messy. I was going to clean up the race. So just to summarize a bit. We have very first thing we have at the time. That’s the word you want to talk about into these I’ll just tell you what it is.

This is Anthony. And then we have the interview by. So basically the type means it’s a category. So the person was the specific entity that the guy whose name Caleb now wasn’t it was the person that we all saw the entity Joe or Billy or whatever his name was. Those were two separate people two separate entities although you could tell that they were somewhat similar.

They were both in the same table.They were both talking about the username password and so forth. So the Inzaghi time is user a specific entity would be cable or Bill or Jane or Jake or whoever it is. So the internet time is basically in the category of the entities that have restoring the categories of user and all of the all the entities within it should be a user. So my camera stop recording by itself for some reason which is super annoying. But anyway so the type is the category of entities such as user.

Every single entity should be a user. Cable was a user. Billy was a user of Jimmy John we could have got Katherine we could have Caitlin we could have Casandra we can have you get one naturally types basically the categories of attributes. So we had the user name we had the the name we had the password of these or attribute types because we don’t actually have a specific value.

It’s like no one’s name is name. When we actually give these specific values they no longer become types and they become specific examples. So this guy over here here is our anti gun store. So basically here’s a recipe we can store attributes about this entity the user name can be Caleb curry. The name could be Caleb and the password can be PI 2:59. So these are specific attributes about that guy. Now all these are all complex terms and who really cares what really matters is can you put this into a table for people to understand who really cares if you know the terms of it.

I mean I’m sure your professor cares so make him anyways. Table to columns or the attributes so we can have for example an idea a password a user name and email. We can keep going address phone number and whatever else. And then a row is where we give the value for every single one of these attributes. All talking about one entity. So like this guy this guy right here. Well as you do for example 72. His user name is Caitlin curry. His email is cool guy at hotmail dot com blah blah blah blah blah. All of this row talks about this guy.

So basically just think attributes are comb’s entities or individual. So sweet. And then this whole thing right here. This is the table and that is the entity type so the entity type was the user because every single row in this table should be user. Oh another thing I would like to mention real quick of another name in mathematics for a row is a tumble or a tuple. I think it’s trouble.

I don’t know but that is another term you will hear. So yeah Tuttle is a thinking sorry for like yelling Get all intense fun right. So that’s the lesson in this video. If you want to subscribe you better do that like right now with scribe. And if you haven’t subscribed yet you better subscribe and also click like subscribe. Thank you and I will see you guys in the next video where we’ll be talking about relational database management systems.

Another big word which we will explain shortly. So see around.



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